A chemist wishes to ship the chemic

A chemist wishes to ship the chemicals a,b,c,d,e,f, and x using as few containers as possible. Certain chemicals cannot be shipped in the same container since they will react with each other. In particular,any two of the chemicals a,b,c and x react with each other. Further, A and E both react with F and D. Describe a graph that models these relations between the chemicals. Use this graph to find the minimum number of container needed to ship the chemical.